Instrument or display device having markings rendered fluorescent by invisible light rays



Dec. 23, 1952 v J 5, RUSSELL 2,623,182

INSTRUMENT 0R DISPLAY DEVICE HAVING MARKINGS RENDERED FLUORESCENT BY INVISIBLE LIGHT RAYS Filed June 9. 1949 1 //V VENTOR Patented Dec. 23, 1952 'INSTRUMENT R DISPLAY DEVICE HAVING 'MARKINGS RENDERED FLUORESCENT BY INVISIBLE LIGHT RAYS :Vic'tor James "Samuel Russell, Cricklewood, Lonifdo'n, ,England, assignor to S. Smith & Sons jtEng' la'nd') Limited, London,'-England, a British company A111 licatio.n diune,9, 1949, Serial No; 98,044 In Great'Britain July 9, 1948 Claims. 21

This invention relatesltoinstruments or. display devices havingmarkings which may be rendered fluorescent, by suitable 'light'r'ays outside or nearly outside the visible spectrum,,.such as ultra-violet or infra-red rays. The. more usual wayof illuminating markings onlinstruments islby the reflection therefrom of ftheI-lig'ht of invi'sible wavelength. Such illumination, however suffers-from the disadvantage that the light which-does not actually strike the markings is reflected and scattered by other partsaof the instruments and results in a general levelof; illumination which is undesirable, and also in {reducing the contrast between the markings and their surroundings.

In order to avoid these objections, ithas been proposed .to illuminatethe whole of the instrument face or dialwit'h ultra-violet raysand coat the markings along with ta substance which is fluorescent in ultra-violet: rays. However, when the source of .ultra-violetrays J'requir'es to be located comparatively close-otothe plane in which the markings are situated and to oneside of the markings, asfor instance in the case of a dashboard instrument.-- fo r;a vehicle, there; is difficulty in :ensuring wthatgsufiicient radiation reaches all the markings, particularly if any, of the markings are sunk below'the general level or the dial plate of the instrument which -is the case when the markings-arexona drumviewablethrough a window in the dialeplate. It isthe object of the present inventiontoprovide-means for overcoming the above difficulty.

According to this invention, an-instrument or display device having markings which-are arranged to be renderedifluorescent by-asource of invisible light radiation disposed ,in ,front of and/or'to one side of the markings, is-characterised in the provision-of oneor more reflectors so located in the neighbourhoodpofthe markingsas to direct the invisibleraysfon to them without their being obscured to view by the reflectors.

In the. case wheresaid markings areon-amovmg part arrangedubehind adial plate having a window through "which the 1-markings 1 may be viewed as. they movesuccessivelyin front, of the window, the aforesaid reflector orrrefiectorsmay be mounted at or near that edge of the window which isremote from the-source of invisible light rays; for example, thereflector may be formed by bending or pressing outwardly-apart of the 1 plate which J may .be iormed from 1-metal-and polished to provide the-necessary reflecting surface.

The plate mayalso .bezformedwith a slot on that side of the window adjacent the source of 2. invisible light rays, so that the rays may pass through the slot directly on t'ofthe markings. viewable, through thewindo'w.

Thejaforesaid slot maybe arranged adjacent to the window. and may be. obscured to direct view by a shroud so that'the markings are not viewable through the slot. Again, in'this instance, the shroud may be formed'by suitably slitting-the plate and bending a portion outwardly whereby both 'a'slot and a shroud areprovided.

The instrument is ,alsoprovided with mileage recorders'in the form of drums I3 arranged with their axes horizontal and parallel with the dialplate which is provided witha window 14 opposite each set of drums, sothat the figures are viewable. "The-assemblage being arranged within a casing it; having a cover plate 16. It will be appreciatcd, therefore, that the figures on the drums are, necessarily recessed back fromthefrontface of the dial-plate l I. Both the graduations on the dial-plate H and thefigures on the mileage recorder drums. it are coated with acomposition which is rendered fluorescent by ultra-violet rays. The twosets of drums may be arranged one above the other, and two ultra-violet lamps 7 I! are mounted on the instrument board 2 one above and the other below the instrument. Owing to the limitation of space for mounting the instruments, the ulra-violetlampscan usually only be mounted slightly injfront cf the planepf the dial-plate H. "'Inorder'to ensure adequate irradiation of. the figures on each set of mileage recorder drums, a reflector is'formedalong the lower edge of, the upper window and the upper edge ofv the lower window. This maybe effected .by slitting the material of thedial-plate and bending it outwardly at 18 at suchan angle as to reflect the ultra-violenraysfrom the adjacent lamp rearwardly through the window. For this purpose, the dial-plate may be formed from metal which may be polished on the back face, at least along those parts constituting the reflectors l8, while the front face is preferably non-reflecting.

In order still further to increase the illumination of the figures on the mileage recorder drums, the material of the dial-plate II is so slit between the upper window I4 and the adjacent lamp H and between the lower window I4 and its adjacent lamp II, that flaps [9 may be bent outwardly adjacent each window at a comparatively small angle so as to obscure to view the slots 29 formed beneath them, but permitting the ultra-violet rays from the adjacent lamps to pass through windows 2! in the casing I and through the slots 20 on to the drum. For this purpose, the upper flap is joined to the dial-plate along its lower edge, whereas the lower flap is joined to the dial-plate along its upper edge.

t will be appreciated that if necessary or more convenient, the flaps and the reflectors may be formed separately and secured to the dial-plate.

I claim:

1. A display device comprising a moving part bearing markings adapted to be rendered fluorescent by a source of invisible light rays disposed to one side of said markings, a mask having a window arranged opposite said moving part and a reflector mounted along one side of the window remote from said source and to one side of the direct line between the source and the markings so as to direct on to the markings, viewable through the window, those rays which would otherwise pass clear of them.

2. A display device comprising a moving part bearing markings adapted to be rendered fluorescent by a source of invisible light rays disposed to one side of said markings, a sheet metal mask having a window arranged opposite said moving part which sheet metal part is so shaped along one side of the window as to form a reflector remote from said source and to one side of the direct line between the source and the markings so as to direct on to the markings, viewable through the window, those rays which would otherwise pass clear of them.

3. A display device comprising a moving part bearing markings adapted to be rendered fluorescent by a source of light rays disposed to one side of said markings, a mask having a window arranged opposite said moving part, a reflector along one side of the window arranged opposite said moving part, a reflector along one side of the window remote from said source and to one side of the direct line between the source and the markings so as to direct on to the markings viewable through the window those rays which would otherwise pass clear of them, and which mask is provided with a slot on that side of the window adjacent the aforesaid source so that the rays may pass through the slot directly on to the mask viewable through the window.

4. A display device comprising a moving part bearing markings adapted to be rendered fluorescent by a source of light rays disposed to one side of said markings, a mask having a window arranged opposite said moving part, a reflector along one side of the window remote from said source and to one side of the direct line between the source and the markings, viewable through the window so as to direct on to the markings those rays which would otherwise mask the others, and which mask is provided with a slot on that side of the window adjacent the aforesaid source so that the rays may pass through the slot directly on to the mask viewable through the window, and a shroud arranged over the mask so 4 that the markings are not directly viewed through the slot.

5. A display device comprising a moving part bearing markings adapted to be rendered fluorescent by a source of invisible light rays disposed to one side of said markings, a mask having a window arranged opposite said moving part, which mask is so shaped as to provide a reflector along that side of the window remote from said source and to one side of the direct line between the source and the markings so as to direct on to the markings, viewable through the Window those rays which wouldv otherwise pass clear of them, and which mask is slit and bent adjacent the opposite side of the window so as to provide a slot through which the rays may pass direct to the aforesaid markings.

6. A milometer comprising a milometer drum bearing markings adapted to be rendered fluorescent by a source of invisible light rays disposed to one side thereof, a mask in front of said drum having a window through which said markings can be traversed, a reflector along one side of said window and to one side of the direct line between the source and said markings so as to direct on to the markings those rays which would otherwise pass clear of them.

7. A milometer comprising a milometer drum bearing markings adapted to be rendered fluorescent by a source of invisible light rays disposed to one side thereof, a mask in front of said drum having a window through which said markings can be traversed, a reflector along one side of said window and to one side of the direct line between the source and the markings so as to direct on to the markings those rays which would otherwise pass clear of them, and which mask is provided with a slot near the opposite side of the window through which said light rays may pass direct to said markings.

8. A combined milometer and speedometer comprising a milometer drum having markings adapted to be rendered fluorescent by a source of invisible light rays disposed to one side thereof, a mask arranged in front of said drum, having a window through which said markings are visible, a speedometer scale on the front of this mask, a reflector on said mask arranged along one side of the window and to one side of the direct line between the source and the markings so as to direct on to the markings those rays which would otherwise pass clear of them.

9. A combined milometer and speedometer comprising two sets of milometer drums arranged one above the other and rotatable about parallel axes, a mask arranged in front of the drums and provided with a window opposite the markings on each set of drums, a reflector along the lower edge of the upper window and along the upper edge of the lower window, a casing containing the said drums and masks, windows in the upper and lower edges of said casing, a source of invisible light rays opposite each window which reflectors are arranged to one side of the direct line between each light source and in the markings so as to direct on to the markings those rays which would otherwise pass clear .of them.

10. A combined milometer and speedometer comprising two sets of milometer drums arranged one above the other and rotatable about parallel axes, a mask arranged in front of the drum and provided with a window opposite the markings on each set of drums, a reflector along the lower edge of the upper window and along the upper edge of the lower window, a casing containing the said drums and masks, windows in the upper and lower edges of said casing, a source of invisible light rays opposite each window, which mask is provided with slots from the top window and a slot below the lower window, and a shroud disposed opposite to each slot which reflectors are arranged to one side of the direct line between each light source and in the markings so as to direct on to the markings those rays which would otherwise pass clear of them.

VICTOR JAMES SAMUEL RUSSELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

